package com.kevin.ms.redis;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.alibaba.fastjson.JSON;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;

/**
 * Redis操作Service类
 *
 * @author Kevin Liu
 * @date 2020/1/5 20:40
 * @see JedisPool
 * @since 1.0
 */
@Service
public class RedisService {

    @Autowired
    private JedisPool jedisPool;

    /**
     * 获取单个对象
     *
     * @param prefix key前缀
     * @param key    key
     * @param clazz  返回的class对象
     * @return {@link T}
     * @author kevin
     * @date 2020/1/5 20:41
     * @since 1.0
     */
    public <T> T get(KeyPrefix prefix, String key, Class<T> clazz) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            String str = jedis.get(realKey);
            T t = stringToBean(str, clazz);
            return t;
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 设置对象
     *
     * @param prefix 前缀
     * @param key    key
     * @param value  value
     * @return {@link Boolean}
     * @author kevin
     * @date 2020/1/5 20:42
     * @since 1.0
     */
    public <T> boolean set(KeyPrefix prefix, String key, T value) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String str = beanToString(value);
            if (str == null || str.length() <= 0) {
                return false;
            }
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            int seconds = prefix.expireSeconds();
            if (seconds <= 0) {
                jedis.set(realKey, str);
            } else {
                jedis.setex(realKey, seconds, str);
            }
            return true;
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 判断Key是否存在
     *
     * @param prefix 前缀
     * @param key    key
     * @return {@link boolean}
     * @author kevin
     * @date 2020/1/5 20:43
     * @since 1.0
     */
    public <T> boolean exists(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.exists(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 增加值
     */
    public <T> Long incr(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.incr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 减少值
     */
    public <T> Long decr(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.decr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * pojo转String
     *
     * @param value value
     * @return {@link String}
     * @author kevin
     * @date 2020/1/5 20:44
     * @since 1.0
     */
    private <T> String beanToString(T value) {
        if (value == null) {
            return null;
        }
        Class<?> clazz = value.getClass();
        if (clazz == int.class || clazz == Integer.class) {
            return "" + value;
        } else if (clazz == String.class) {
            return (String) value;
        } else if (clazz == long.class || clazz == Long.class) {
            return "" + value;
        } else {
            return JSON.toJSONString(value);
        }
    }

    /**
     * str转pojo
     *
     * @param str 转化前字符串
     * @param clazz 转化后的对象
     * @return {@link T}
     * @author kevin
     * @date 2020/1/5 20:45
     * @since 1.0
     */
    @SuppressWarnings("unchecked")
    private <T> T stringToBean(String str, Class<T> clazz) {
        if (str == null || str.length() <= 0 || clazz == null) {
            return null;
        }
        if (clazz == int.class || clazz == Integer.class) {
            return (T) Integer.valueOf(str);
        } else if (clazz == String.class) {
            return (T) str;
        } else if (clazz == long.class || clazz == Long.class) {
            return (T) Long.valueOf(str);
        } else {
            return JSON.toJavaObject(JSON.parseObject(str), clazz);
        }
    }

    /**
     * 关闭jedis
     *
     * @param jedis jedis连接对象
     * @return void
     * @author kevin
     * @date 2020/1/5 20:46
     * @since 1.0
     */
    private void returnToPool(Jedis jedis) {
        if (jedis != null) {
            jedis.close();
        }
    }

}
